1. Field of the Invention
The present invention is directed to a method for operating a magnetic resonance (MR) tomography apparatus.
2. Description of the Related Art
Heretofore the implementation of a magnetic resonance (MR) examination has ensued interactively. Overview (planning) images are registered at the beginning of the examination. The slices/volumes to be examined are then defined based on these overview images. Saturation slices are also defined in many examinations in order, for example, to avoid artifacts due to fat tissue. These saturation slices are also defined by the user of the apparatus on the basis of the anatomical details seen in the overview images. It often occurs that the slices to be measured and other image parameters cannot yet be adequately defined on the basis of the overview images. One person therefore usually must be available during the entire examination time only for operating the apparatus. Typically, this person cannot attend to any other jobs for the time of the examination.
High demands are made as to the qualifications of the operator since the diagnostic content of the exposures that are obtained is greatly dependent on the positioning of the slices to be measured and on the saturation slices (if required) as well as on other parameters to be set (slice thickness, number of slices, distance between the slices, observation window, size of the measuring matrix, etc.).
This job is in fact somewhat facilitated by making prepared measuring protocols available, which already contain pre-settings. Typically, image parameters such as matrix size, type of pulse sequence, repetition time, etc., are thereby prescribed. Nonetheless, the adaptation of these prepared measuring protocols to a specific examination case requires the input of a number of parameters, which requires the interaction of a specifically trained and experienced operator during the entire measuring time.
U.S. Pat. No. 5,818,231 discloses a method for the quantification and standardization of magnetic resonance measurements. The method can be employed for medical as well as for industrial magnetic resonance applications and can define the value of a continuous property such as concentration, viscosity or the like. This occurs by interpolation or extrapolation from a model that was in turn derived from training datasets. Pattern recognition methods are thereby employed. A number of low-resolution scan are interpreted instead of identifying material composition with a single, high-resolution scan. The combination of such scans, which are implemented with different modalities, generally leads to more exact results than a single high-resolution scan.
It is an object of the present invention to provide a method that simplifies the operation of an MR tomography apparatus and makes interaction of the operator largely unnecessary during the execution of the measurement or scan.
The above object is achieved in accordance with the principles of present invention in a method for operating magnetic resonance tomography apparatus, wherein the tomography apparatus determines anatomical landmarks in the examination subject automatically on the basis of a specific diagnostic interrogatory which is predetermined and entered by an operator, and the tomography apparatus also automatically determines measuring parameters for the following magnetic resonance measurements on the basis of these landmarks.
In the inventive method, the user need only indicate the diagnostic question (inquiry or interrogatory) for standard examinations; the entire measuring procedure then sequences automatically. For standard examinations, the operator therefore can turn to other tasks during the measuring time, for example operating a second MR apparatus. Fewer demands are made on the operator, at least for standard measurements.
The method can be especially advantageously utilized when the inquiry refers to a specific organ whose position and expanse in the examination subject is determined by the MR apparatus on the basis of a comparison of an overview exposure to stored patterns. The measuring parameters that are optimum for the organ to be imaged thus can be independently determined by the MR tomography apparatus.